Given:

n2 + 3h2 → 2nh3

bond bond energy (kj/mol)

n≡n 942

h–h 432

n–h 386

use the bond energies to calculate the change in enthalpy for the reaction.

the enthalpy change for the reaction is kilojoules. express answer in 2 sig figs

ΔH = -78 kj/mol

Explanation:

Given data:

Bond energies:

N≡N = 942 kJ/mol

H-H = 432 kj/mol

N-H = 386 kj/mol

Change in enthalpy of reaction = ?

Solution:

N₂ + 3H₂  → 2NH₃

942 + 3×432   =  2(386×3)

942+1296 = 2316

2238 = 2316

ΔH = Bond broken - bond formed

ΔH = 2238  kj/mol - 2316 kj/mol

ΔH = -78 kj/mol

a) the particles of the chair are strongly held together.

2b2t

explanation:

2b2t